Cameras are commonly used to capture an image of a scene that includes one or more objects. Unfortunately, some of the images are blurred. For example, movement of the camera and/or movement of the objects in the scene during the exposure time of the camera can cause the image to be blurred. Further, if the camera is not properly focused when the image is captured, that image will be blurred.
As digital photography becomes more and more popular, image quality assessment such as sharpness measurement has been a topic of great interest. Sharpness is generally described as the measurement of either the clarity of details or the transition of edges inside image. Currently, there are certain methods based on measuring sharp information inside the image that are used to evaluate the sharpness of an image. Unfortunately, existing methods do not accurately and consistently evaluate the level of sharpness over a broad variety of images. For example, conventional methods easily fail to detect blurry night scene images with the presence of saturated light trails due to the fact that the light trails result in “false” sharp information.